Semiconductor device and method for manufacturing semiconductor device

ABSTRACT

A semiconductor device includes a semiconductor element, a lead frame, a conductive member, a resin composition and a sealing resin. The semiconductor element has an element front surface and an element back surface facing away in a first direction. The semiconductor element is mounted on the lead frame. The conductive member is bonded to the lead frame, electrically connecting the semiconductor element and the lead frame. The resin composition covers a bonded region where the conductive member and lead frame are bonded while exposing part of the element front surface. The sealing resin covers part of the leadframe, the semiconductor element, and the resin composition. The resin composition has a greater bonding strength with the lead frame than a bonding strength between the sealing resin and lead frame and a greater bonding strength with the conductive member than a bonding strength between the sealing resin and conductive member.

TECHNICAL FIELD

The present disclosure relates to a semiconductor device and a methodfor manufacturing a semiconductor device.

BACKGROUND ART

A conventional semiconductor device is disclosed in Patent Document 1.The semiconductor device disclosed in Patent Document 1 includes asemiconductor element, a lead frame, solder, a wire, and a sealingresin. In the semiconductor device, the semiconductor element may be adiode chip or a MOSFET (Metal Oxide Semiconductor Field EffectTransistor). The semiconductor element is mounted on the lead frame, andthe lead frame is electrically connected to the semiconductor elementwith the solder or the wire. The solder and wire serve as conductivemembers that electrically connect the lead frame and the semiconductorelement. That is, solder is interposed between the semiconductor elementand the lead frame, electrically connecting these. The wire is bonded tothe semiconductor element and the lead frame, electrically connectingthese. The sealing resin covers part of the lead frame, thesemiconductor element, the solder, and the wire.

TECHNICAL REFERENCE Patent Document

-   Patent Document 1: JP-A-2017-5165

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

A semiconductor device may be subjected to thermal load applied due toe. g. ref lowing in mounting the semiconductor device to a circuit boardof an electronic device or due to heat generated from the semiconductorelement during operation. Thermal stress due to such thermal loadconcentrates on the bonded region where the conductive members such assolder or a wire and the lead frame are bonded. Such concentration ofthermal stress may cause the sealing resin to be detached at theinterface between the bonded region and the sealing resin. If a thermalload is further applied with the sealing resin detached, cracks canoccur in the solder as a conductive member. Also, the wire as aconductive member can be detached or broken. These may causemalfunctions of the semiconductor device.

The present disclosure has been proposed under the above-notedcircumstances, and an object of the present disclosure is to provide asemiconductor device and a method for manufacturing a semiconductordevice which prevent the detachment of the sealing resin due to thermalload and thereby prevent malfunctions.

Means for Solving the Problems

In accordance with a first aspect of the present disclosure, there isprovided a semiconductor device including: a semiconductor elementhaving an element front surface and an element back surface facing awayfrom each other in a first direction; a lead frame on which thesemiconductor element is mounted; a conductive member bonded to the leadframe, the conductive member electrically connecting the semiconductorelement and the lead frame; a resin composition covering a bonded regionwhere the conductive member and the lead frame are bonded while exposingpart of the element front surface; and a sealing resin covering part ofthe lead frame, the semiconductor element and the resin composition. Theresin composition has a greater bonding strength with the lead framethan a bonding strength between the sealing resin and the lead frame andalso has a greater bonding strength with the conductive member than abonding strength between the sealing resin and the conductive member.

In a preferable embodiment of the semiconductor device, the lead frameincludes a die pad and a lead spaced apart from the die pad, the die padhaving a pad front surface facing a direction in which the element frontsurface faces and a pad back surface facing a direction in which theelement back surface faces, and the semiconductor element is mounted onthe die pad, with the pad front surface and the element back surfacefacing each other.

In a preferable embodiment of the semiconductor device, thesemiconductor element includes a back-surface electrode formed on theelement back surface, the conductive member includes a conductivebonding material bonding the semiconductor element and the die pad andelectrically connecting the back-surface electrode and the die pad, andthe resin composition includes a die-pad-side covering portion coveringa bonded region where the conductive bonding material and the die padare bonded.

In a preferable embodiment of the semiconductor device, the conductivebonding material has an element contact surface in contact with theback-surface electrode, a die-pad contact surface in contact with thedie pad, and a connecting surface connected to the element contactsurface and the die-pad contact surface, and the die-pad-side coveringportion includes a die-pad-side first portion interposed between theconnecting surface and the sealing resin.

In a preferable embodiment of the semiconductor device, the die-pad-sidecovering portion further includes a due-pad-side second portionconnected to the die-pad-side first portion and interposed between thepad front surface and the sealing resin.

In a preferable embodiment of the semiconductor device, thesemiconductor element has an element side surface connected to theelement front surface and the element back surface, and the die-pad-sidecovering portion further includes a die-pad-side third portion connectedto the die-pad-side first portion and interposed between at least partof the element side surface and the sealing resin.

In a preferable embodiment of the semiconductor device, the die-pad-sidecovering portion further includes a die-pad-side fourth portionconnected to the die-pad-side third portion and interposed between partof the element front surface and the sealing resin.

In a preferable embodiment of the semiconductor device, the conductivebonding material comprises solder.

In a preferable embodiment of the semiconductor device, the pad backsurface is exposed from the sealing resin.

In a preferable embodiment of the semiconductor device, thesemiconductor element includes a front-surface electrode formed on theelement front surface, the conductive member includes a wire bonded tothe front-surface electrode and the lead to electrically connect thefront-surface electrode and the lead, and the resin composition includesa lead-side covering portion covering a bonded region where the wire andthe lead are bonded.

In a preferable embodiment of the semiconductor device, the wireincludes a first bond part bonded to the front-surface electrode and asecond bond part bonded to the lead, and the lead-side covering portionincludes a lead-side first portion interposed between the second bondpart and the sealing resin.

In a preferable embodiment of the semiconductor device, the lead-sidecovering port ion further includes a lead-side second port ion connectedto the lead-side first portion and interposed between the lead and thesealing resin.

In a preferable embodiment of the semiconductor device, the wire furtherincludes a line part connecting the first bond part and the second bondpart, and the line part includes a sealing-resin contact region that isin contact with the sealing resin along an entire circumference thereof.

In a preferable embodiment of the semiconductor device, thesemiconductor element is a power semiconductor chip.

In accordance with a second aspect of the present disclosure, there isprovided a method for manufacturing a semiconductor device, where themethod includes: a step of preparing a lead frame; a step of preparing asemiconductor element having an element front surface and an elementback surface facing away from each other in a first direction; anelement mounting step of mounting the semiconductor element on theleadframe; a conductive member provision step of bonding a conductivemember to the lead frame and the semiconductor element to electricallyconnect the lead frame and the semiconductor element with the conductivemember; an application step of applying a paste composite material so asto cover a bonded region where the conductive member and the lead frameare bonded while exposing part of the element front surface; a step ofdrying the applied paste composite material; and a step of forming asealing resin covering part of the lead frame, the semiconductor elementand the dried paste composite material. The paste composite materialcontains a resin material. The resin material has a greater bondingstrength with the lead frame than a bonding strength between the sealingresin and the lead frame and also has a greater bonding strength withthe conductive member than a bonding strength between the sealing resinand the conductive member.

In a preferable embodiment of the method for manufacturing asemiconductor device, the lead frame includes a die pad and a leadspaced apart from the die pad, the die pad having a pad front surfacefacing a direction in which the element front surface faces and a padback surface facing a direction in which the element back surface faces,and the element mounting step comprises mounting the semiconductorelement on the die pad, with the pad front surface and the element backsurface facing each other.

In a preferable embodiment of the method for manufacturing asemiconductor device, the semiconductor element includes a back-surfaceelectrode formed on the element back surface. The conductive memberprovision step comprises applying a conductive paste that bonds theback-surface electrode and the die pad before the element mounting step,and drying the conductive paste after the element mounting step to forma conductive bonding material that bonds the semiconductor element andthe die pad and electrically connects the back-surface electrode and thedie pad. The application step comprises applying the paste compositematerial so as to at least cover a bonded region where the conductivebonding material and the die pad are bonded.

In a preferable embodiment of the method for manufacturing asemiconductor device, the semiconductor element includes a front-surfaceelectrode formed on the element front surface, the conductive memberprovision step comprises providing a wire bonded to the front-surfaceelectrode and the lead to electrically connect the front-surfaceelectrode and the lead after the element bonding step, and theapplication step comprises applying the paste composite material so asto at least cover a bonded region where the wire and the lead arebonded.

Advantages of the Invention

With the semiconductor device of the present disclosure, detachment ofthe sealing resin due to thermal load is prevented, so that malfunctionsare prevented. Also, the manufacturing method according to the presentdisclosure makes it possible to manufacture a semiconductor device thatprevents malfunctions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a semiconductor device according toa first embodiment;

FIG. 2 is a perspective view corresponding to FIG. 1 , with a sealingresin and a resin composition omitted;

FIG. 3 is a plan view showing the semiconductor device according to thefirst embodiment;

FIG. 4 is a plan view obtained by omitting the sealing resin from FIG. 3;

FIG. 5 is a front view showing the semiconductor device according to thefirst embodiment;

FIG. 6 is a bottom view showing the semiconductor device according tothe first embodiment;

FIG. 7 is a side view (right side view) showing the semiconductor deviceaccording to the first embodiment;

FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 4;

FIG. 9 is a sectional view taken along line IX-IX in FIG. 4 ;

FIG. 10 is a sectional view taken along line X-X in FIG. 4 ;

FIG. 11 shows a step of a method for manufacturing the semiconductordevice according to the first embodiment;

FIG. 12 shows a step of a method for manufacturing the semiconductordevice according to the first embodiment;

FIG. 13 shows a step of a method for manufacturing the semiconductordevice according to the first embodiment;

FIG. 14A is a schematic sectional view showing a structure in whichsealing resin is directly formed on the conductive bonding material;

FIG. 14B shows a structure in which a resin composition is interposedbetween the conductive bonding material and the sealing resin;

FIG. 15 is a plan view showing a semiconductor device according to asecond embodiment (with the sealing resin omitted);

FIG. 16 is a sectional view showing the semiconductor device accordingto the second embodiment;

FIG. 17 is a perspective view showing a semiconductor device accordingto a third embodiment;

FIG. 18 is a perspective view corresponding to FIG. 17 , with a sealingresin and a resin composition omitted;

FIG. 19 is a plan view showing the semiconductor device according to thethird embodiment;

FIG. 20 is a plan view obtained by omitting the sealing resin from FIG.19 ;

FIG. 21 is a front view showing the semiconductor device according tothe third embodiment;

FIG. 22 is a bottom view showing the semiconductor device according tothe third embodiment;

FIG. 23 is a sectional view taken along line XXIII-XXIII in FIG. 20 ;

FIG. 24 is a sectional view taken along line XXIV-XXIV in FIG. 20 ;

FIG. 25 is a plan view showing a semiconductor device according to afourth embodiment;

FIG. 26 is a partially enlarged view of FIG. 25 ;

FIG. 27 is a sectional view taken along line XXVII-XXVII in FIG. 25 ;

FIG. 28 is a sectional view taken along line XXVIII-XXVIII in FIG. 25 ;

FIG. 29 is a plan view showing a semiconductor device according to afifth embodiment;

FIG. 30 is a sectional view taken along line XXX-XXX in FIG. 29 ; and

FIG. 31 is a sectional view taken along line XXXI-XXXI in FIG. 29 .

MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of a semiconductor device and a method formanufacturing a semiconductor device according to the present disclosureare described below with reference to the drawings.

FIGS. 1-10 show a semiconductor device according to a first embodimentof the present disclosure. The semiconductor device A1 of the firstembodiment includes a semiconductor element 1, a lead frame 2, aplurality of wires 3, a conductive bonding material 4, a sealing resin 5and a resin composition 6. The wires 3 include a plurality of firstwires 31, a second wire 32 and a third wire 33.

FIG. 1 is a perspective view of the semiconductor device A1. FIG. 2 is aperspective view corresponding to FIG. 1 , with the sealing resin 5 andthe resin composition 6 omitted. FIG. 3 is a plan view of thesemiconductor device A1. FIG. 4 is a plan view obtained by omitting thesealing resin 5 from FIG. 3 . Note that in FIG. 4 the resin composition6 is indicated by imaginary lines (and applied with dot patterns for theconvenience of understanding). FIG. 5 is a front view of thesemiconductor device A1. FIG. 6 is a bottom view of the semiconductordevice A1. FIG. 7 is a side view (right side view) of the semiconductordevice A1. FIG. 8 is a sectional view taken along line VIII-VIII in FIG.4 . FIG. 9 is a sectional view taken along line IX-IX in FIG. 4 . FIG.10 is a sectional view taken along line X-X in FIG. 4 . For theconvenience of description, the three directions that are orthogonal toeach other are defined as x direction, y direction and z direction,respectively. The x direction is the horizontal direction in plan view(see FIGS. 3 and 4 ). They direction is the vertical direction in planview (see FIGS. 3 and 4 ). The z direction is the thickness (height)direction of the semiconductor device A1.

The semiconductor element 1 is an electronic component that performs themain function of the semiconductor device A1 and made of a semiconductormaterial. Examples of the semiconductor material include, withoutlimitation, Si (silicon), SiC (silicon carbide) and GaAs (galliumarsenide). The semiconductor element 1 is a power semiconductor chipsuch as a MOSFET. The present embodiment shows the example in which thesemiconductor element 1 is a MOSFET, but the present disclosure is notlimited to this, and the semiconductor element may be other types oftransistors such as an IGBT (insulated gate bipolar transistor) or adiode such as a Schottky barrier diode or a fast recovery diode. In thepresent disclosure, a power semiconductor chip is defined as asemiconductor chip configured to be used under the conditions in whichthe product of the voltage and the current is 1 W or more, where thevoltage is the one across an input terminal and an output terminal andthe current is the one flowing between the input terminal and the outputterminal. In a MOSFET, the input terminal and the output terminal are adrain electrode and a source electrode, respectively. As shown in FIG. 4, the semiconductor element 1 is, for example, rectangular as viewed inplan. As shown in FIGS. 4, 8 and 9 , the semiconductor element 1 has anelement front surface 1 a, an element back surface 1 b and a pluralityof element side surfaces 1 c.

The element front surface 1 a and the element back surface 1 b arespaced apart and face away from each other in the z direction. Each ofthe element side surfaces 1 c is located between the element frontsurface 1 a and the element back surface 1 b. One edge of each elementside surface 1 c in the z direction (the upper edge in FIGS. 8 and 9 )is connected to the element front surface 1 a, and the other edge ofeach element side surface in the z direction (the lower edge in FIGS. 8and 9 ) is connected to the element back surface 1 b. All of the elementfront surface 1 a, the element back surface 1 b and the element sidesurfaces 1 c are generally flat. In the present embodiment, thesemiconductor element 1 has a pair of element side surfaces 1 c facingaway from each other in the x direction and a pair of element sidesurfaces 1 c facing away from each other in the y direction.

As shown in FIGS. 2, 4, 8 and 9 , the semiconductor element 1 includes aplurality of front-surface electrodes 11 and a back-surface electrode12. In this way, the semiconductor element 1 is of a vertical structuretype. The front-surface electrodes 11 are formed on the element frontsurface 1 a. As shown in FIGS. 2 and 4 , the front-surface electrodes 11include a first front-surface electrode 111, a second front-surfaceelectrode 112 and a third front-surface electrode 113. The back-surfaceelectrode 12 is formed on the element back surface 1 b. The firstfront-surface electrode 111 is a source electrode, the secondfront-surface electrode 112 is agate electrode, the third front-surfaceelectrode 113 is a source sense electrode, and the back-surfaceelectrode 12 is a drain electrode. The arrangement, size and shape ofthe first front-surface electrode 111, the second front-surfaceelectrode 112 and the third front-surface electrode 113 are not limitedto those shown in the figures. The third front-surface electrode 113(source sense electrode) may not be formed. The material for thefront-surface electrodes 11 (the first front-surface electrode 111, thesecond front-surface electrode 112 and the third front-surface electrode113) and the back-surface electrode 12 may be A1 (aluminum), forexample.

The lead frame 2, on which the semiconductor element 1 is mounted, iselectrically connected to the semiconductor element 1. When mounted on acircuit board of an electronic device for example, the lead frame 2forms an electrical conduction path between the semiconductor element 1and the circuit board. The lead frame 2 is made of a conductivematerial. The conductive material may be Cu (copper), for example. Theconductive material is not limited to Cu, and may be Ni (nickel), Cualloy, Ni alloy, or 42 alloy, for example. The lead frame 2 is formed byworking a metal plate such as a copper plate that is rectangular asviewed in plan into an appropriate shape by punching, cutting orbending, for example. As shown in FIGS. 2 and 4 , the lead frame 2includes a first lead 21, a second lead 22, a third lead 23 and a diepad 24. In the lead frame 2, these parts are spaced apart from eachother.

The first lead 21 is the part of the lead frame 2 that is electricallyconnected to the first front-surface electrode 111 (source electrode) ofthe semiconductor element 1. The first lead 21 is electrically connectedto the first front-surface electrode 111 with the first wires 31. Asshown in FIGS. 2, 4 and 8 , the first lead 21 includes a wire bondingportion 211 and a plurality of terminal portions 212.

One end of each of the first wires 31 is bonded to the wire bondingportion 211. The wire bonding portion 211 is covered with the sealingresin 5.

The terminal portions 212 are connected to the wire bonding portion 211.Part of each terminal portion 212 is exposed from the sealing resin 5.The plurality of terminal portions 212 have the same shape except one.Note however that all terminal portions 212 of the first lead 21 mayhave a same shape. As viewed in the x direction, the terminal portions212 overlap with each other. The terminal portions 212 are bonded to acircuit board to function as the source terminal of the semiconductordevice A1. As shown in FIGS. 1-6 , the first lead 21 has five terminalportions 212. The number, length and shape of the terminal portions 212are not limited to the example shown in the figures.

The second lead 22 is the part of the lead frame 2 that is electricallyconnected to the second front-surface electrode 112 (gate electrode) ofthe semiconductor element 1. The second lead 22 is electricallyconnected to the second front-surface electrode 112 with the second wire32. As shown in FIGS. 2 and 4 , the second lead 22 includes a wirebonding portion 221 and a terminal portion 222.

One end of the second wire 32 is bonded to the wire bonding portion 221.The wire bonding portion 221 is covered with the sealing resin 5.

The terminal portion 222 is connected to the wire bonding portion 221.Part of the terminal portion 222 is exposed from the sealing resin 5.The part of the terminal portion 222 that is exposed from the sealingresin 5 is partially bent. As viewed in the x direction, the terminalportion 222 overlaps with the terminal portions 212. The terminalportion 222 is bonded to a circuit board to function as the gateterminal of the semiconductor device A1.

The third lead 23 is the part of the lead frame 2 that is electricallyconnected to the third front-surface electrode 113 (source senseelectrode) of the semiconductor element 1. The third lead 23 iselectrically connected to the third front-surface electrode 113 with thethird wire 33. As shown in FIGS. 2 and 4 , the third lead 23 includes awire bonding portion 231 and a terminal portion 232.

One end of the third wire 33 is bonded to the wire bonding portion 231.The wire bonding portion 231 is covered with the sealing resin 5.

The terminal portion 232 is connected to the wire bonding portion 231.Part of the terminal portion 232 is exposed from the sealing resin 5.The part of the terminal portion 232 that is exposed from the sealingresin 5 is partially bent. As viewed in the x direction, the terminalportion 232 overlaps with the terminal portions 212 and the terminalportion 222. In the x direction, the terminal portions 232 is locatedbetween the terminal portions 212 and the terminal portions 222. Theterminal portion 232 is bonded to a circuit board to function as thesource sense terminal of the semiconductor device A1.

The die pad 24 is the part of the lead frame 2 on which thesemiconductor element 1 is mounted. Part of die pad 24 is covered withthe sealing resin 5, while the other part is exposed from the sealingresin 5. As shown in FIGS. 8 and 9 , the die pad 24 has a pad frontsurface 24 a and a pad back surface 24 b.

The pad front surface 24 a and the pad back surface 24 b are spacedapart and face away from each other in the z direction. The pad frontsurface 24 a faces the direction in which the element front surface 1 afaces. The pad front surface 24 a faces the element back surface 1 b.The pad back surface 24 b faces the direction in which the element backsurface 1 b faces. The pad back surface 24 b is exposed from the sealingresin 5.

The die pad 24 is electrically connected to the back-surface electrode12 (the drain electrode) with the conductive bonding material 4. The diepad 24 is bonded to a circuit board to function as the drain terminal ofthe semiconductor device A1.

The first wires 31, the second wire 32 and the third wire 33 areconnecting members that electrically connect the semiconductor element 1and the lead frame 2.

The first wires 31 are bonding wires containing A1. Specifically, thefirst wires 31 may be made of A1 alloy containing e.g. Fe (iron), Si orNi, or pure A1. Alternatively, the first wires 31 may be bonding wirescontaining Cu or Au (gold) instead of A1. Also, the first wires 31 maynot be bonding wires but may be bonding ribbons. The present embodimentshows the example in which the semiconductor device A1 has two firstwires 31, but the number of the first wires 31 is not limited. Thediameter of each first wires 31 is e.g. about 400 μm. As shown in FIGS.2, 4 and 8 , each of the first wires 31 includes a first bond part 311,a second bond part 312 and a line part 313.

The first bond part 311 is one end of each first wire 31 that is bondedto the first front-surface electrode 111 of the semiconductor element 1.As shown in FIGS. 2, 4 and 8 , the first bond part 311 includes a frontcontact portion 311 a, a rear contact portion 311 b and an intermediateportion 311 c. The front contact portion 311 a and the rear contactportion 311 b are both in contact with the first front-surface electrode111. The front contact portion 311 a is on the farther side from thesecond bond part 312, whereas the rear contact portion 311 b is on thecloser side to the second bond part 312. The intermediate portion 311 cis located between the front contact portion 311 a and the rear contactportion 311 b. The intermediate portion 311 c is not bonded to the firstfront-surface electrode 111 but is slightly raised above the firstfront-surface electrode 111 to have an arcuate shape. In this way, thefirst bond part 311 is in contact with the first front-surface electrode111 at two locations (i.e., includes the front contact portion 311 a andthe rear contact portion 311 b) in the present embodiment, but the firstbond part may be in contact with the first front-surface electrode 111at one location.

The second bond part 312 is the other end of each first wire 31 that isbonded to the wire bonding portion 211 of the first lead 21. The secondbond part 312 is covered with the resin composition 6.

The line part 313 extends from each of the first bond part 311 and thesecond bond part 312, connecting the first bond part 311 and the secondbond part 312. The line part 313 is circular in cross section orthogonalto the longitudinal direction. The line part 313 includes aresin-composition contact region 313 a and a sealing-resin contactregion 313 b. The resin-composition contact region 313 a is covered withthe resin composition 6. The resin-composition contact region 313 a isin contact with the resin composition 6 along the entire circumference.The sealing-resin contact region 313 b is not covered with the resincomposition 6 but covered with the sealing resin 5. The sealing-resincontact region 313 b is in contact with the sealing resin 5 along theentire circumference.

The first wires 31 electrically connect the first front-surfaceelectrode 111 and the first lead 21. In the semiconductor device A1, thefirst wires 31 and the first front-surface electrode 111 are both madeof metal containing A1. Thus, the influence of thermal stress is smallat the regions where these are bonded.

The second wire 32 is a bonding wire containing Au. Alternatively, thesecond wire 32 may be a bonding wire containing A1 or Cu instead of Au.The diameter of the second wire 32 is smaller than that of the firstwires 31. That is, the second wire 32 is thinner than the first wires31. The diameter of the second wire 32 is e.g. about 50 to 75 μm. Thediameter of the second wire 32 may be varied as appropriate inaccordance with the material for the second wire 32. As shown in FIG. 4, the second wire 32 includes a first bond part 321, a second bond part322 and a line part 323.

The first bond part 321 is one end of the second wire 32 that is bondedto the second front-surface electrode 112 of the semiconductor element1.

The second bond part 322 is the other end of the second wire 32 that isbonded to the wire bonding portion 221.

The line part 323 extends from each of the first bond part 321 and thesecond bond part 322, connecting the first bond part 321 and the secondbond part 322. The line part 323 is circular in cross section orthogonalto the longitudinal direction.

The second wire 32 electrically connects the second front-surfaceelectrode 112 and the second lead 22.

The third wire 33 is a bonding wire containing Au. Alternatively, thethird wire 33 may be a bonding wire containing A1 or Cu instead of Au.The third wire 33 is made of the same material and has the same diameteras the second wire 32, but may be made of a different material and havea different diameter from the second wire 32. The diameter of the thirdwire 33 may be varied as appropriate in accordance with the material forthe third wire 33. As shown in FIG. 4 , the third wire 33 includes afirst bond part 331, a second bond part 332 and a line part 333.

The first bond part 331 is one end of the third wire 33 that is bondedto the third front-surface electrode 113 of the semiconductor element 1.When the front-surface electrode 11 does not include the thirdfront-surface electrode 113 (source sense electrode), the first bondpart 331 may be bonded to the first front-surface electrode 111 (sourceelectrode) to enable detection of the source current.

The second bond part 332 is the other end of the third wire 33 that isbonded to the wire bonding portion 231.

The line part 333 extends from each of the first bond part 331 and thesecond bond part 332, connecting the first bond part 331 and the secondbond part 332. The line part 333 is circular in cross section orthogonalto the longitudinal direction.

The third wire 33 electrically connects the third front-surfaceelectrode 113 and the third lead 23.

The conductive bonding material 4 bonds the semiconductor element 1 tothe lead frame 2. As shown in FIGS. 8 and 9 , the conductive bondingmaterial 4 is interposed between the element back surface 1 b of thesemiconductor element 1 and the pad front surface 24 a of the die pad24, electrically connecting the back-surface electrode 12 of thesemiconductor element 1 and the die pad 24. The conductive bondingmaterial 4 is solder, for example. The type of the solder is notparticularly limited, and examples of the solder include lead-freesolders such as Sn—Sb alloys or Sn—Ag alloys, and lead-containingsolders such as Sn—Pb alloys.

As shown in FIGS. 8 and 9 , the conductive bonding material 4 has anelement contact surface 4 a, a die-pad contact surface 4 b and aconnecting surface 4 c. The element contact surface 4 a is in contactwith the element back surface 1 b of the semiconductor element 1. Theelement contact surface 4 a may be generally flat. The die-pad contactsurface 4 b is in contact with the pad front surface 24 a of the die pad24. The die-pad contact surface 4 b may be generally flat. Theconnecting surface 4 c is located between the element contact surface 4a and the die-pad contact surface 4 b, connecting these contactsurfaces. The connecting surface 4 c may be generally flat or may becurved. As shown in FIGS. 8 and 9 , the connecting surface 4 c isinclined with respect to the element contact surface 4 a and the die-padcontact surface 4 b. The angle formed by the element contact surface 4 aand the connecting surface 4 c is about 0.3° to 27°, for example. Thedimension (thickness) ΔH (see FIG. 9 ) of the conductive bondingmaterial 4 in the z direction is about 10 to 150 μm, for example. Theprotruding dimension ΔL (see FIG. 9 ), i.e., the amount by which theconductive bonding material 4 protrudes outward from each element sidesurface 1 c as viewed in plan is about 300 to 2000 μm, for example. Notethat the above-described angle and dimensions ΔH, ΔL are the values thatinclude manufacturing errors and can be measured with the manufacturedsemiconductor device A1. As the design values at the time ofmanufacture, the above angle may be about 1 to 15°, the dimension ΔH ofthe conductive bonding material 4 in the z direction may be about 30 to130 μm, and the protruding dimension ΔL of the conductive bondingmaterial 4 may be about 500 to 1500 μm, for example.

The sealing resin 5 covers the semiconductor element 1, part of the leadframe 2, the wires 3 and the resin composition 6. The sealing resin 5 isa thermosetting synthetic resin that is electrically insulative. Thesealing resin 5 may be made of a black epoxy resin mixed with a filler.The filler may be a particulate filler having a particle diameter ofabout 75 μm, for example. As shown in FIGS. 1, 3 and 5-10 , the sealingresin 5 has a resin front surface 5 a, a resin back surface 5 b and aplurality of resin side surfaces 5 c.

The resin front surface 5 a and the resin back surface 5 b are spacedapart and face away from each other in the z direction. The resin frontsurface 5 a faces the direction in which the element front surface 1 afaces, and the resin back surface 5 b faces the direction in which theelement back surface 1 b faces. Each of the resin side surfaces 5 c islocated between the resin front surface 5 a and the resin back surface 5b. One edge of each resin side surface 5 c in the z direction isconnected to the resin front surface 5 a, and the other edge of eachresin side surface in the z direction is connected to the resin backsurface 5 b. In the present embodiment, the sealing resin 5 has a pairof resin side surfaces 5 c spaced apart from each other in the xdirection and a pair of resin side surfaces 5 c spaced apart from eachother in the y direction.

In the present embodiment, the first lead 21, the second lead 22 and thethird lead 23 project from one of the resin side surfaces 5 c. Also,part of the die pad 24 projects from another resin side surface 5 c.Specifically, as viewed in plan, the first, the second and the thirdleads 22, 23, 24 and the die pad 24 project from mutually opposite resinside surfaces 5 c of the sealing resin 5. The pad back surface 24 b ofthe die pad 24 is exposed from the resin back surface 5 b.

The resin composition 6 is provided to cover the bonded region where theconductive bonding material 4 and the die pad 24 are bonded, and thebonded region where the first wires 31 and the first lead 21 are bonded.The resin composition 6 has a greater bonding strength with the leadframe 2 than the bonding strength between the sealing resin 5 and thelead frame 2. Also, the resin composition 6 has a greater bondingstrength with the conductive bonding material 4 than the bondingstrength between the sealing resin 5 and the conductive bonding material4, and a greater bonding strength with the wires 3 than the bondingstrength between the sealing resin 5 and the wires 3. The superiority orinferiority of the bonding strength may be determined based on “puddingcup strength” (unit: Mpa). The pudding cup strength represents the shearstrength of a resin material (e.g; material for the resin composition 6or the sealing resin 5) formed into the shape of a pudding cup and heldin close contact with a bonding target (e.g., material for the leadframe 2, the conductive bonding material 4 or the wires 3). A higherpudding cup strength indicates a greater bonding strength, and a lowerpudding cup strength indicates a lower bonding strength. The resincomposition 6 may be made of a material containing, for example, athermoplastic resin, an epoxy resin, a coupling agent, a powderedinorganic filler, and powders with rubber elasticity. The resincomposition 6 is e.g. about 10 to 20 μM in thickness. The material andthickness of the resin composition 6 are not limited to those describedabove. As shown in FIGS. 4 and 8 , the resin composition 6 includes adie-pad-side covering portion 61 and a lead-side covering portion 62.The die-pad-side covering portion 61 and the lead-side covering portion62 are spaced apart from each other.

The die-pad-side covering portion 61 covers the bonded region where theconductive bonding material 4 and the die pad 24 are bonded.Hereinafter, this bonded region is referred to as a die-pad-side bondedregion. As shown in FIGS. 4, 8 and 9 , the die-pad-side covering portion61 includes a die-pad-side first portion 611, a die-pad-side secondportion 612 and a die-pad-side third portion 613. The die-pad-side firstportion 611, the die-pad-side second portion 612 and the die-pad-sidethird portion 613 are integrally formed.

As shown in FIG. 8 , the die-pad-side first portion 611 is interposedbetween the connecting surface 4 c of the conductive bonding material 4and the sealing resin 5.

As shown in FIG. 8 , the die-pad-side second portion 612 is interposedbetween the pad front surface 24 a of the die pad 24 and the sealingresins. The die-pad-side second portion 612 is connected to thedie-pad-side first portion 611. Specifically, the die-pad-side secondportion 612 is connected to the lower edge in the z direction of thedie-pad-side first portion 611. In the present embodiment, thedie-pad-side second portion 612 covers only part of the portion of thepad front surface 24 a that is not in contact with the die-pad contactsurface 4 b of the conductive bonding material 4. However, thedie-pad-side second portion may cover the entirety of the portion of thepad front surface 24 a that is not in contact with the die-pad contactsurface 4 b of the conductive bonding material 4.

As shown in FIG. 8 , the die-pad-side third portion 613 is interposedbetween each element side surface 1 c of the semiconductor element 1 andthe sealing resin 5. The die-pad-side third portion 613 is connected tothe die-pad-side first portion 611. Specifically, the die-pad-side thirdportion 613 is connected to the upper edge in the z direction of thedie-pad-side first portion 611. In the present embodiment, as viewed inthe x direction or the y direction, the die-pad-side third portion 613is located below the element front surface 1 a in the z direction.

The lead-side covering portion 62 covers the bonded region where thefirst wires 31 and the first lead 21 are bonded. Hereinafter, thisbonded region is referred to as a lead-side bonded region. As shown inFIGS. 4 and 8 , the lead-side covering portion 62 includes a lead-sidefirst portion 621, a lead-side second portion 622 and a lead-side thirdportion 623. The lead-side first portion 621, the lead-side secondportion 622 and the lead-side third portion 623 are integrally formed.

As shown in FIG. 8 , the lead-side first portion 621 is interposedbetween the second bond part 312 of each first wire 31 and the sealingresin 5.

As shown in FIG. 8 , the lead-side second portion 622 is interposedbetween the wire bonding portion 211 of the first lead 21 and thesealing resin 5. The lead-side second portion 622 is connected to thelead-side first portion 621.

As shown in FIG. 8 , the lead-side third portion 623 is interposedbetween a part of the line part 313 (the resin-composition contactregion 313 a) of each first wire 31 and the sealing resin 5.Specifically, the lead-side third portion 623 is formed on a part of theline part 313 that is offset toward the second bond part 312. Thelead-side third portion 623 is connected to the lead-side first portion621.

A method for manufacturing the semiconductor device A1 is describedbelow with reference to FIGS. 11-13 . Note that in FIGS. 11-13 , theelements that are identical or similar to those shown in FIGS. 1-10 aredenoted by the same reference signs as those used in FIGS. 1-10 .

First, as shown in FIG. 11 , a lead frame 200 and a semiconductorelement 1 are prepared. The prepared lead frame 200 includes a firstlead 21, a second lead 22, a third lead 23 and a die pad 24, which areconnected to each other by a frame part 201. The lead frame 200 may havea size that allows production of a plurality of semiconductor devicesA1. A MOSFET having a vertical structure is prepared as thesemiconductor element 1, but a MOSFET having a horizontal structure maybe prepared instead. The semiconductor element 1 is formed with a firstfront-surface electrode 111, a second front-surface electrode 112 and athird front-surface electrode 113 on the element front surface 1 a, anda back-surface electrode 12 on the element back surface 1 b.

Next, as shown in FIG. 12 , the semiconductor element 1 is mounted onthe die pad 24 via a conductive bonding material 4. In this step ofmounting the semiconductor element 1 (element mounting step), aconductive paste is applied to the pad front surface 24 a of the die pad24. In the present embodiment, solder paste is used as the conductivepaste. Next, the semiconductor element 1 is placed on the appliedconductive paste. At this time, the semiconductor element 1 is placed,with the pad front surface 24 a and the element back surface 1 b facingeach other. Next, the conductive paste is baked, whereby the conductivebonding material 4 is formed, and the mounting of the semiconductorelement 1 onto the die pad 24 is thus completed. The conductive bondingmaterial 4 bonds and electrically connects the lead frame 200 (die pad24) and the semiconductor element 1 (back-surface electrode 12).

Next, as shown in FIG. 12 , the first wires 31, the second wire 32 andthe third wire 33 are bonded to the semiconductor element 1 and the leadframe 200. Bonding these wires 3 uses a known wire bonder. The presentembodiment describes wedge bonding using a wedge tool, but ball bondingusing a capillary may be employed. The first wires 31 are bonding wirescontaining A1 as the main ingredient. The second wire 32 and the thirdwire 33 are bonding wires containing Au as the main ingredient. One endof each first wire 31 is bonded to the first front-surface electrode111, and the other end of each first wire 31 is bonded to the wirebonding portion 211 of the first lead 21. One end of the second wire 32is bonded to the second front-surface electrode 112, and the other endof the second wire 32 is bonded to the wire bonding portion 221 of thesecond lead 22. One end of the third wire 33 is bonded to the thirdfront-surface electrode 113, and the other end of the third wire 33 isbonded to the wire bonding portion 231 of the third lead 23. The orderin which the first wires 31, the second wire 32 and the third wire 33are bonded is not limited.

The step of bonding each first wire 31 may be performed as follows.First, while the tip of a wedge is pressed against the firstfront-surface electrode 111, ultrasonic vibration is applied. By thisprocess, one end of the first wire 31 is fused, due to ultrasonicenergy, onto the first front-surface electrode 111, whereby the frontcontact portion 311 a is formed. Next, the wedge is slightly moved whiledispensing the first wire 31 from the tip of the wedge, and then the tipof the wedge is again pressed against the first front-surface electrode111 while ultrasonic vibration is applied. This process forms theintermediate portion 311 c and the rear contact portion 311 b, wherebythe first bond part 311 is completed. Next, the wedge is moved whiledispensing the first wire 31 from the tip of the wedge, whereby the linepart 313 is formed. Next, while the first wire 31 is pressed against thewire bonding portion 211 of the first lead 21, ultrasonic vibration isapplied. By this process, the other end of the first wire 31 is fused,due to ultrasonic energy, onto the wire bonding portion 211. Next, thewedge is slightly moved, and a cut is made in the first wire 31 with acutter of the wedge tool. The wedge along with the first wire 31 is thenfurther moved away from the wire bonding portion 211, causing the firstwire 31 to be cut. Thus, the second bond part 312 is formed. In thisway, one end (first bond part 311) of the first wire 31 is bonded to thefirst front-surface electrode 111, and the other end (second bond part312) of the first wire 31 is bonded to the wire bonding portion 211.Thus, the first front-surface electrode 111 and the wire bonding portion211 (first lead 21) are electrically connected to each other with thefirst wire 31. Note that the steps of bonding the second wire 32 and thethird wire 33 are generally the same as the bonding steps of the firstwires 31.

Next, the resin composition 6 is formed, as shown in FIG. 13 . To formthe resin composition 6, a paste composite material is applied to thearea where the resin composition 6 is to be formed. The step of applyingthe paste composite material (application step) may be performed using ajet dispenser, for example. Instead of using a jet dispenser, theapplication step may be performed by other application techniques suchas spray coating or spin coating, or by screen printing, for example. Inthe present embodiment, the paste composite material is applied to thesurface region of the conductive bonding material 4 around thesemiconductor element 1, as viewed in plan. The paste composite materialincludes at least a resin material and an organic solvent. The resinmaterial has a greater bonding strength with the lead frame 200 than thebonding strength between the sealing resin 5 and the lead frame 200.Also, the resin material has a greater bonding strength with the wires 3than the bonding strength between the sealing resin 5 and the wires 3,and a greater bonding strength with the conductive bonding material 4than the bonding strength between the sealing resin 5 and conductivebonding material 4. In the present embodiment, the paste compositematerial may contain a thermoplastic resin, an epoxy resin, a couplingagent, a powdered inorganic filler, powders with rubber elasticity, andan organic solvent, for example. The applied paste composite material isthen dried to allow the organic solvent to be volatilized, whereby thesolidified resin composition 6 is obtained.

Next, the sealing resin 5 is formed. The sealing resin 5 may be formedby molding using a mold, for example. As the material for the sealingresin 5, use may be made of an epoxy resin mixed with a particulatefiller. After the sealing resin 5 is formed, the lead frame 200 is cutfor division into individual pieces for the semiconductor elements 1.Before or after cutting the lead frame 200, various processes may beperformed as appropriate such as a process to improve the strengthagainst bending of the lead frame 2 at portions exposed from the sealingresin 5, a process to improve adhesion to a printed board during themounting, exterior treatment for rust prevention, lead working to bendthe lead frame 2 into a predetermined shape at portions exposed from thesealing resin 5, a stamping process to stamp a company name, a productname, a lot number, etc. on the sealing resin 5, and aninspection/sorting process to determine the quality of the products.Note that these processes may be performed as appropriate in accordancewith the specification of the final semiconductor device A1.

By going through the steps described above, the semiconductor device A1shown in FIGS. 1-10 is obtained.

The advantages of the semiconductor device A1 according to the firstembodiment are described below.

The semiconductor device A1 includes the resin composition 6. The resincomposition 6 covers the bonded region (e.g., the die-pad-side bondedregion or the lead-side bonded region) where the conductive members(e.g., the conductive bonding material 4 or the first wires 31) and thelead frame 2 are bonded. The bonding strength between the resincomposition 6 and the lead frame 2 is greater than the bonding strengthbetween the sealing resin 5 and the lead frame 2. Also, the bondingstrength between the resin composition 6 and the conductive members isgreater than the bonding strength between the sealing resin 5 and theconductive members. With such an arrangement, the resin composition 6serves as an adhesive to improve the bonding strength between theabove-described bonded region and the sealing resin 5. Thus, even when athermal load is applied to the semiconductor device A1, detachmentbetween the bonded region and the sealing resin 5 is prevented. Thus, inthe semiconductor device A1, malfunctions due to detachment of thesealing resin 5 are prevented.

In the semiconductor device A1, the element front surface 1 a of thesemiconductor element 1 is exposed from the resin composition 6. Thatis, the element front surface 1 a is not covered with the resincomposition 6. During the operation of the semiconductor device A1, thesemiconductor element 1 tends to generate heat in proximity to theelement front surface 1 a side. If the element front surface 1 a iscovered with the resin composition 6, such heat generated in proximityto the element front surface 1 a tends to be retained in the case wherethe thermal conductivity of the resin composition 6 is lower than thatof the sealing resin 5. This increases the temperature difference at theinterface between the resin composition 6 and the element front surface1 a. The thermal stress, caused by such an increased temperaturedifference, may cause malfunctions of the semiconductor device A1. Thus,when the thermal conductivity of the resin composition 6 is lower thanthat of the sealing resin 5, exposing the element front surface 1 a fromthe resin composition 6 makes the temperature difference at theinterface of the element front surface 1 a smaller, as compared withwhen the element front surface 1 a is covered with the resin composition6. Thus, in the semiconductor device A1, malfunctions due to thetemperature difference are prevented.

In the method for manufacturing the semiconductor device A1, the pastecomposite material is applied with a jet dispenser. This enablesselective application of the paste composite material, allowing theresin composition 6 to be formed at selected regions. Specifically, itis possible to avoid the element front surface 1 a of the semiconductorelement 1 during the application of the paste composite material asshown in FIG. 13 , which enables formation of the resin composition 6that does not cover the element front surface 1 a as shown in FIG. 4 .In this way, it is possible to manufacture the semiconductor device A1that prevents malfunctions due to the temperature difference describedabove.

In the semiconductor device A1, the resin composition 6 includes thedie-pad-side covering portion 61, and the die-pad-side covering portion61 covers the bonded region (die-pad-side bonded region) where theconductive bonding material 4 and the lead frame 2 (die pad 24) arebonded. With such a structure, the die-pad-side covering portion 61improves the bonding strength between the die-pad-side bonded region andthe sealing resin 5, preventing detachment between the die-pad-sidebonded region and the sealing resin 5. If such a detachment occurs, anincreased thermal stress is exerted on the conductive bonding material 4when a thermal load is exerted on the semiconductor device A1, which mayresult in cracking of the conductive bonding material 4. Such crackingmay deteriorate heat dissipation and electrical conductivity of theconductive bonding material 4. Since the semiconductor device A1prevents detachment between the die-pad-side bonded region and thesealing resin 5, the thermal stress exerted on the conductive bondingmaterial 4 is reduced, which prevents cracking of the conductive bondingmaterial 4. By preventing cracking of the conductive bonding material 4in this way, the semiconductor device A1 prevents deterioration of heatdissipation and electrical conductivity of the conductive bondingmaterial 4. It is known that solder containing lead generally has ahigher physical strength against thermal stress than lead-free solder.For this reason, conventional semiconductor devices often use soldercontaining lead for the conductive bonding material 4 to improveresistance to thermal cycles. In the semiconductor device A1, provisionof the die-pad-side covering portion 61 (resin composition 6) reducesthe thermal stress exerted on the conductive bonding material 4 asdescribed above, so that resistance to thermal cycles is secured evenwhen lead-free solder is used for the conductive bonding material 4.Thus, the semiconductor device A1 provides improved resistance tothermal cycles, with environmental protection taken into consideration.

In the semiconductor device A1, the die-pad-side covering port ion 61includes the die-pad-side first portion 611 interposed between theconnecting surface 4 c of the conductive bonding material 4 and thesealing resin 5. With such an arrangement, the bonding strength betweenthe conductive bonding material 4 and the sealing resin 5 is improved bythe die-pad-side first portion 611.

FIGS. 14A and 14B are schematic views for explaining the mechanism ofhow the bonding strength between the conductive bonding material 4 andthe sealing resin 5 is improved by the resin composition 6 (die-pad-sidefirst portion 611). FIG. 14A shows a structure in which the sealingresin 5 is directly formed on the conductive bonding material 4, i.e.,the structure of a conventional semiconductor device, whereas FIG. 14Bshows a structure in which the resin composition 6 is interposed betweenthe conductive bonding material 4 and the sealing resin 5, i.e., thestructure of the semiconductor device A1.

As shown in FIG. 14A, the conductive bonding material 4 has a roughsurface with fine grooves 40. The grooves 40 are smaller than theparticle size of the filler 51 mixed in the sealing resin 5. Thus, whenthe sealing resin 5 is directly formed on the surface of the conductivebonding material 4, the filler 51 mixed in the sealing resin 5 may closethe grooves 40 so that the grooves 40 are not filled with the sealingresin 5. The grooves 40 that are not filled with the sealing resin 5 inthis way form air gaps at the interface between the conductive bondingmaterial 4 and the sealing resin 5, which may lead to deterioration ofthe bonding strength.

In contrast, as shown in FIG. 14B, when the resin composition 6 isinterposed between the conductive bonding material 4 and the sealingresin 5, the grooves 40 in the surface of the conductive bondingmaterial 4 are filled with the resin composition 6. In this way, theresin composition 6 prevents formation of air gaps, so thatdeterioration of the bonding strength due to air gaps is avoided.Further, filling the grooves 40 with the resin composition 6 provides ananchoring effect that improves the bonding strength with the conductivebonding material 4. Moreover, hydrogen bonds are formed at the interfacebetween the resin composition 6 and the sealing resin 5, which providesa good bonding strength between the resin composition 6 and the sealingresin 5. In this way, the bonding strength between the conductivebonding material 4 and the sealing resin 5 is improved by interposingthe resin composition 6 between the conductive bonding material 4 andthe sealing resin 5.

In the semiconductor device A1, the die-pad-side covering portion 61includes the die-pad-side second portion 612 interposed between the padfront surface 24 a of the die pad 24 and the sealing resin 5. With suchan arrangement, the bonding strength between the die pad 24 and thesealing resin 5 is improved by the die-pad-side second portion 612. Thesurface of the lead frame 2 has fine grooves as with the conductivebonding material 4. Thus, the bonding strength between the die pad 24and the sealing resin 5 is improved by the same principle as thatexplained with reference to FIGS. 14A and 14B.

In the semiconductor device A1, the die-pad-side covering portion 61includes the die-pad-side third portion 613 interposed between eachelement side surface 1 c and the sealing resin 5. With such anarrangement, the bonding strength between the element side surfaces 1 cand the sealing resin 5 is improved by the die-pad-side third portion613. The element side surfaces 1 c have fine grooves as with theconductive bonding material 4. Thus, the bonding strength between theelement side surfaces 1 c and sealing resin 5 is improved by the sameprinciple as that explained with reference to FIGS. 14A and 14B.

In the semiconductor device A1, the resin composition 6 includes thelead-side covering portion 62, and the lead-side covering portion 62covers the bonded region (lead-side bonded region) where each of thefirst wires 31 (each of the second bond parts 312) and the lead frame 2(wire bonding portion 211 of the first lead 21) are bonded. With such anarrangement, the lead-side covering portion 62 improves the bondingstrength between the lead-side bonded region and the sealing resin 5,preventing detachment between the lead-side bonded region and thesealing resin 5. If such a detachment occurs, an increased thermalstress is exerted on the second bond part 312 of each first wire 31 whena thermal load is exerted on the semiconductor device A1, which mayresult in the first wire 31 detaching from the wire bonding portion 211.Since the semiconductor device A1 prevents detachment between thelead-side bonded region and the sealing resin 5, exertion of anincreased thermal stress on the second bond part 312 of each first wire31 is avoided, so that each first wire 31 is prevented from detachingfrom the wire bonding portion 211. When each first wire 31 is made ofmetal containing A1, a passivation film (oxide film) is formed on thesurface of the first wire 31, protecting the wire from corrosion.However, when detachment between the lead-side bonded region and thesealing resin 5 occurs, the first wire 31 and the sealing resin 5 rubagainst each other, which may cause damage to the passivation film onthe surface of the first wire 31. In such a case, corrosion progressesfrom the damaged portion of the passivation film, causing deteriorationof the electrical conductivity or breakage of the first wire 31. In thesemiconductor device A1, however, the lead-side covering portion 62functions as a protective member to protect the first wires 31 fromcorrosion, so that deterioration of the electrical conductivity orbreakage of the first wires 31 is prevented.

In the semiconductor device A1, the lead-side covering portion 62includes the lead-side first portion 621 interposed between the secondbond part 312 of each first wire 31 and the sealing resin 5. With suchan arrangement, the bonding strength between the second bond part 312and the sealing resin 5 is improved by the lead-side first portion 621.

In the semiconductor device A1, the lead-side covering portion 62includes the lead-side second portion 622 interposed between the wirebonding portion 211 (first lead 21) and the sealing resin 5. With suchan arrangement, the bonding strength between the wire bonding portion211 (first lead 21) and the sealing resin 5 is improved by the lead-sidesecond portion 622. The surface of the lead frame 2 (first lead 21) hasfine grooves as with the conductive bonding material 4. Thus, thebonding strength between the wire bonding portion 211 and the sealingresin 5 is improved by the same principle as that explained withreference to FIGS. 14A and 14B.

In the semiconductor device A1, the lead-side covering portion 62includes the lead-side third portion 623 interposed between a part ofthe line part 313 of each first wire 31 and the sealing resin 5. Withsuch an arrangement, the bonding strength between the line part 313 ofeach first wire 31 and the sealing resin 5 is improved by the lead-sidethird portion 623.

In the semiconductor device A1, the first wires 31 are made of metalcontaining A1, whereas the first lead 21 is made of metal containing Cu.The first wires 31 are bonded to the first lead 21 (wire bonding portion211). When such different types of metals are bonded, the difference incoefficient of thermal expansion (coefficient of linear thermalexpansion) causes a larger thermal stress to be exerted on the firstwires 31 (second bond part 312) than when the same type of metals arebonded, so that detachment between the lead-side bonded region and thesealing resin 5 is more likely to occur. Accordingly, in order toprevent the detachment between the lead-side bonded region and thesealing resin 5, the provision of the resin composition 6 including thelead-side covering portion 62 is more effective when the first wires 31and the first lead 21 are made of different types of metals, as comparedwith when the first wires 31 and the first lead 21 are made of the sametype of metal.

In the semiconductor device A1, the pad back surface 24 b of the die pad24 is exposed from the sealing resin 5. Such exposure of the die pad 24from the sealing resin 5 causes the die pad 24 to undergo a greaterthermal expansion than when there is no exposure. As a result, anincreased thermal stress is exerted on the die-pad-side bonded region,so that the sealing resin 5 is more likely to be detached at thedie-pad-side bonded region. Accordingly, the provision of thedie-pad-side covering portion 61 to prevent the detachment of thesealing resin 5 due to thermal stress on the die-pad-side bonded regionis particularly effective for the semiconductor device A1 in which thepad back surface 24 b of the die pad 24 is exposed from the sealingresin 5.

In the semiconductor device A1, the semiconductor element 1 is a powersemiconductor chip such as a MOSFET. Power semiconductor chips haverelatively high resistance to large currents and voltages, but generatea large amount of heat. Such heat generation can cause theabove-described detachment of the sealing resin 5. Thus, the provisionof the resin composition 6 to prevent the detachment of the sealingresin 5 is particularly effective for the semiconductor device A1 inwhich a power semiconductor chip is mounted as the semiconductor element1.

The first embodiment shows the example in which the resin composition 6includes both the die-pad-side covering portion 61 and the lead-sidecovering portion 62, but either one alone may suffice. For example, whenthe resin composition 6 includes the die-pad-side covering portion 61alone, the presence of the resin composition 6 (die-pad-side coveringportion 61) between the die-pad-side bonded region and the sealing resin5 improves the bonding strength between the die-pad-side bonded regionand the sealing resin 5. In this case, the step of applying the pastecomposite material (application step) may be performed before the stepof bonding the first wires 31, the second wire 32 and the third wire 33.On the other hand, when the resin composition 6 includes the lead-sidecovering portion 62 alone, the presence of the resin composition 6(lead-side covering portion 62) between the lead-side bonded region andthe sealing resin 5 improves the bonding strength between the lead-sidebonded region and the sealing resin 5. When the resin composition 6 isformed to include only one of the die-pad-side covering portion 61 andthe lead-side covering portion 62 in this way, the manufacturing costand the manufacturing steps are reduced because forming the other one isnot necessary.

The first embodiment shows the example in which the lead-side coveringportion 62 of the resin composition 6 covers the bonded region of thefirst wires 31 and the first lead 21, but the present disclosure is notlimited to this. For example, a resin composition 6 covering the bondedregion of the second wire 32 and the second lead 22 may be providedinstead of or in addition to the lead-side covering portion 62. Such anarrangement prevents detachment of the sealing resin 5 from the bondedregion of the second wire 32 and the second lead 22. Also, a resincomposition 6 covering the bonded region of the third wire 33 and thethird lead 23 may be provided instead of or in addition to the lead-sidecovering portion 62. Such an arrangement prevents detachment of thesealing resin 5 from the bonded region of the third wire 33 and thethird lead 23.

FIGS. 15-31 show other embodiments of a semiconductor device and itsmanufacturing method according to the present disclosure. In thesefigures, the elements that are identical or similar to those of thesemiconductor device A1 of the first embodiment are denoted by the samereference signs as those used for the semiconductor device A1, and thedescription thereof is omitted.

FIGS. 15 and 16 show a semiconductor device according to a secondembodiment. The semiconductor device A2 of the second embodiment differsfrom the semiconductor device A1 in formation region of the resincomposition 6. Specifically, as shown in FIGS. 15 and 16 , in the resincomposition 6 of the semiconductor device A2, the die-pad-side coveringportion 61 further includes a die-pad-side fourth portion 614. FIG. 15is a plan view showing the semiconductor device A2 and corresponds toFIG. 4 of the first embodiment. FIG. 16 is a sectional view taken alongline XVI-XVI in FIG. 15 .

As shown in FIGS. 15 and 16 , the die-pad-side fourth portion 614 coverspart of the element front surface 1 a. The die-pad-side fourth portion614 is interposed between the part of the element front surface 1 a andthe sealing resin 5. As shown in FIGS. 15 and 16 , the die-pad-sidefourth portion 614 is connected to the die-pad-side third portion 613.Ina step of manufacturing the semiconductor device A2 (applicationstep), the paste composite material that will become the resincomposition 6 is applied using a jet dispenser, for example. In applyingthe paste composite material, part of the paste composite material maybe put on the element front surface 1 a. The die-pad-side fourth portion614 may be formed of this part of the paste composite material appliedto the element front surface 1 a.

The semiconductor device A2 includes the resin composition 6, as withthe semiconductor device A1. The resin composition 6 covers the bondedregion (e.g., the die-pad-side bonded region or the lead-side bondedregion) where the conductive members (e.g., the conductive bondingmaterial 4 or the first wires 31) and the lead frame 2 are bonded. Thus,in the semiconductor device A2 again, malfunctions due to detachment ofthe sealing resin 5 are prevented, as with the semiconductor device A1.

The second embodiment shows the example in which the first bond part 311of each first wire 31, the first bond part 321 of the second wire 32 andthe first bond part 331 of the third wire 33 are exposed from thedie-pad-side covering portion 61 (resin composition 6), but the presentdisclosure is not limited to this. For example, part or the entirety ofthese bond parts may be covered with the die-pad-side covering portion61 (resin composition 6). However, since source current flows througheach first wire 31, the first wires 31 tend to have a higher temperaturethan the second wire 32 and the third wire 33. Thus, the first wires 31are more likely to be adversely affected by thermal load than are thesecond wire 32 and the third wire 33. Thus, to prevent such adverseeffects of thermal load on the first wires 31, it is desirable to exposeat least the first bond part 331 of each first wire 31 from thedie-pad-side covering portion 61 (resin composition 6).

The second embodiment shows the example in which the die-pad-side fourthportion 614 covers part of the element front surface 1 a, but thepresent disclosure is not limited to this. For example, the die-pad-sidefourth portion 614 may cover the entirety of the element front surface 1a. However, considering that covering the entirety of the element frontsurface 1 a with the die-pad-side fourth portion 614 increases thetemperature difference at the interface of the element front surface 1 aas described before, it is preferable that the die-pad-side fourthportion 614 covers only a part of the element front surface 1 a, ratherthan the entirety of the element front surface 1 a.

FIGS. 17-24 show a semiconductor device according to a third embodiment.The semiconductor device A3 of the third embodiment differs from thesemiconductor device A1 in that it is not provided with a source senseterminal.

FIG. 17 is a perspective view of the semiconductor device A3. FIG. 18 isa perspective view corresponding to FIG. 17 , with the sealing resin 5and the resin composition 6 omitted. FIG. 19 is a plan view of thesemiconductor device A3. FIG. 20 is a plan view obtained by omitting thesealing resin 5 from FIG. 19 . Note that in FIG. 20 the resincomposition 6 is indicated by imaginary lines (and applied with dotpatterns for the convenience of understanding). FIG. 21 is a front viewof the semiconductor device A3. FIG. 22 is a bottom view of thesemiconductor device A3. FIG. 23 is a sectional view taken along lineXXIII-XXIII in FIG. 20 . FIG. 24 is a sectional view taken along lineXXIV-XXIV in FIG. 20 .

In the semiconductor device A3, the semiconductor element 1 has a firstfront-surface electrode 111 and a second front-surface electrode 112 asthe front-surface electrode 11, as shown in FIGS. 18, 20 and 24 . Unlikethe semiconductor element 1 of the first embodiment, the semiconductorelement 1 of this embodiment does not have a third front-surfaceelectrode 113. Accordingly, the semiconductor device A3 does not have athird wire 33 and a third lead 23 for electrically connecting a thirdfront-surface electrode 113 to the outside of the semiconductor device.

In the semiconductor device A3, the first lead 21 does not include aplurality of terminal portions 212 but includes a single terminalportions 212. The number of terminal portions 212 in the semiconductordevice A3 is not limited. As shown in FIGS. 17-22 , in the semiconductordevice A3, the die pad 24 includes a portion projecting from the sealingresin 5 between the terminal portion 212 and the terminal portion 222.The projecting portion may be shorter than the terminal portions 212 and222 as shown in FIGS. 17-22 , or may have the same shape as the terminalportions 212 and 222.

In the semiconductor device A3, the bonded region (the die-pad-sidebonded region or the lead-side bonded region) where the conductivemembers (the conductive bonding material 4 or the first wires 31) andthe lead frame 2 are bonded is covered with the resin composition 6.Thus, in the semiconductor device A3 again, malfunctions due todetachment of the sealing resin 5 are prevented, as with thesemiconductor device A1.

FIGS. 25-28 show a semiconductor device according to a fourthembodiment. The semiconductor device A4 of the fourth embodiment differsfrom the semiconductor device A1 in formation region of the resincomposition 6. Specifically, the resin composition 6 of thesemiconductor device A4 further includes a lead-side covering portion 63and a lead-side covering portion 64. FIG. 25 is a plan view showing thesemiconductor device A4 and corresponds to FIG. 4 of the firstembodiment. FIG. 26 is a partially enlarged view showing a part of FIG.25 . FIG. 27 is a sectional view taken along line XXVII-XXVII in FIG. 25. FIG. 28 is a sectional view taken along line XXVIII-XXVIII in FIG. 25.

In the semiconductor device A4, the second wire 32 and the third wire 33are both bonding wires containing A1. The diameter of the second wire 32and the third wire 33 is e.g. about 125 μm.

As shown in FIGS. 25, 26 and 27 , the lead-side covering portion 63covers the bonded region where the second wire 32 and the second lead 22are bonded. As shown in FIGS. 26 and 27 , the lead-side covering portion63 includes a lead-side first portion 631, a lead-side second portion632 and a lead-side third portion 633. The lead-side first portion 631,the lead-side second portion 632 and the lead-side third portion 633 areintegrally formed.

As shown in FIGS. 26 and 27 , the lead-side first portion 631 isinterposed between the second bond part 322 of the second wire 32 andthe sealing resin 5.

As shown in FIGS. 26 and 27 , the lead-side second portion 632 isinterposed between the wire bonding portion 221 of the second lead 22and the sealing resin 5. The lead-side second portion 632 is connectedto the lead-side first portion 631.

As shown in FIGS. 26 and 27 , the lead-side third portion 633 isinterposed between a part of the line part 323 of the second wire 32 andthe sealing resins. Specifically, the lead-side third portion 633 isformed on a part of the line part 323 that is offset toward the secondbond part 322. The lead-side third portion 633 is connected to thelead-side first portion 631.

As shown in FIGS. 25, 26 and 28 , the lead-side covering portion 64covers the bonded region where the third wire 33 and the third lead 23are bonded. As shown in FIGS. 26 and 28 , the lead-side covering portion64 includes a lead-side first portion 641, a lead-side second portion642 and a lead-side third portion 643. The lead-side first portion 641,the lead-side second portion 642 and the lead-side third portion 643 areintegrally formed.

As shown in FIGS. 26 and 28 , the lead-side first portion 641 isinterposed between the second bond part 332 of the third wire 33 and thesealing resin 5.

As shown in FIGS. 26 and 28 , the lead-side second portion 642 isinterposed between the wire bonding portion 231 of the third lead 23 andthe sealing resin 5. The lead-side second portion 642 is connected tothe lead-side first portion 641.

As shown in FIGS. 26 and 28 , the lead-side third portion 643 isinterposed between a part of the line part 333 of the third wire 33 andthe sealing resins. Specifically, the lead-side third portion 643 isformed on a part of the line part 333 that is offset toward the secondbond part 332. The lead-side third portion 643 is connected to thelead-side first portion 641.

The semiconductor device A4 includes the resin composition 6, as withthe semiconductor device A1. The resin composition 6 covers the bondedregion (the die-pad-side bonded region or the lead-side bonded region)where the conductive members (e.g., the conductive bonding material 4 orthe first wires 31) and the lead frame 2 are bonded. Thus, in thesemiconductor device A4 again, malfunctions due to detachment of thesealing resin 5 are prevented, as with the semiconductor device A1.

In the semiconductor device A4, the resin composition 6 includes thelead-side covering portion 63, and the lead-side covering portion 63covers the bonded region of the second wire 32 and the second lead 22.With such an arrangement, the resin composition 6 serves as an adhesiveto improve the bonding strength between the sealing resin 5 and thebonded region of the second wire 32 and the second lead 22. Thus, thesemiconductor device A4 prevents detachment between the bonded regionand the sealing resin 5. If such a detachment occurs, a thermal stressis exerted on a neck portion of the second wire 32 (i.e., the portionconnecting the second bond part 322 and the line part 323) when athermal load is exerted on the semiconductor device A4, which may resultin breakage of the neck portion. Since the semiconductor device A4prevents detachment between the sealing resin 5 and the bonded region ofthe second wire 32 and the second lead 22, thermal stress exerted on theneck portion is reduced. Thus, the semiconductor device A4 preventsmalfunctions (e.g., breakage of the second wire 32) due to detachment ofthe sealing resin 5. In particular, in the semiconductor device A4, alarge thermal stress can be exerted on the neck portion, because thesecond wire 32 is made of metal containing A1 whereas the second lead 22is made of metal containing Cu. Thus, the provision of the lead-sidecovering portion 63 to reduce the thermal stress on the neck portion iseffective for preventing malfunctions of the semiconductor device A4.

In the semiconductor device A4, the second wire 32 is thinner than eachof the first wires 31. Thus, the second wire 32 is more likely to breakdue to corrosion than the first wires. However, since the resincomposition 6 of the semiconductor device A4 includes the lead-sidecovering portion 63 and the lead-side covering portion 63 functions as aprotective member, corrosion of the second wire 32 (e.g., at the portion(neck portion) connecting the second bond part 322 and the line part323) is prevented. Thus, the semiconductor device A4 prevents breakageof the second wire 32 due to corrosion.

In the semiconductor device A4, the resin composition 6 includes thelead-side covering portion 64, and the lead-side covering portion 64covers the bonded region of the third wire 33 and the third lead 23.With such an arrangement, the resin composition 6 serves as an adhesiveto improve the bonding strength between the sealing resin 5 and thebonded region of the third wire 33 and the third lead 23. Thus, thesemiconductor device A4 prevents detachment between the bonded regionand the sealing resin 5. If such a detachment occurs, a thermal stressis exerted on a neck portion of the third wire 33 (i.e., the portionconnecting the second bond part 332 and the line part 333) when athermal load is exerted on the semiconductor device A4, which may resultin breakage of the neck portion. Since the semiconductor device A4prevents detachment between the sealing resin 5 and the bonded region ofthe third wire 33 and the third lead 23, thermal stress exerted on theneck portion is reduced. Thus, the semiconductor device A4 preventsmalfunctions (e.g., breakage of the third wire 33) due to detachment ofthe sealing resin 5. In particular, in the semiconductor device A4, alarge thermal stress can be exerted on the neck portion, because thethird wire 33 is made of metal containing A1 whereas the third lead 23is made of metal containing Cu. Thus, the provision of the lead-sidecovering portion 64 to reduce the thermal stress on the neck portion iseffective for preventing malfunctions of the semiconductor device A4.

In the semiconductor device A4, the third wire 33 is thinner than eachof the first wires 31. Thus, the third wire 33 is more likely to breakdue to corrosion than the first wires. However, since the resincomposition 6 of the semiconductor device A4 includes the lead-sidecovering portion 64 and the lead-side covering portion 64 functions as aprotective member, corrosion of the third wire 33 (e.g., at the portion(neck portion) connecting the second bond part 332 and the line part333) is prevented. Thus, the semiconductor device A4 prevents breakageof the third wire 33 due to corrosion.

The fourth embodiment shows the example in which the second wire 32 andthe third wire 33 are both made of metal containing A1, but the presentdisclosure is not limited to this. For example, the second wire 32 maybe made of metal containing Cu or metal containing Au. In such a caseagain, the lead-side covering portion 63 serves as an adhesive toimprove the bonding strength between the sealing resin 5 and the bondedregion of the second wire 32 and the second lead 22. Also, the thirdwire 33 may be made of metal containing Cu or metal containing Au. Insuch a case again, the lead-side covering portion 64 serves as anadhesive to improve the bonding strength between the sealing resin 5 andthe bonded region of the third wire 33 and the third lead 23.

FIGS. 29-31 show a semiconductor device according to a fifth embodiment.The semiconductor device A5 of the fifth embodiment differs from thesemiconductor device A4 in formation region of the resin composition 6.Specifically, the resin composition 6 of the semiconductor device A5further includes an element-side covering portion 65. FIG. 29 is a planview showing the semiconductor device A5 and corresponds to FIG. 25 ofthe fourth embodiment. FIG. 30 is a sectional view taken along lineXXX-XXX in FIG. 29 . FIG. 31 is a sectional view taken along lineXXXI-XXXI in FIG. 29 .

The element-side covering portion 65 covers the bonded region where thesecond wire 32 and the second front-surface electrode 112 are bonded,and the bonded region where the third wire 33 and the thirdfront-surface electrode 113 are bonded. As viewed in plan, theelement-side covering portion 65 spreads from each of these bondedregions to the surroundings. As viewed in plan, the element-sidecovering portion 65 overlaps with part of the first front-surfaceelectrode 111 and covers the part of the first front-surface electrode111. However, the element-side covering portion 65 (resin composition 6)does not cover the portion (the region R1 shown in FIG. 29 ) of thefirst front-surface electrode 111 on which the first wires 31 may bebonded. In the example shown in FIG. 29 , the element-side coveringportion 65 is connected to the die-pad-side covering portion 61.However, the element-side covering portion 65 may not be connected tothe die-pad-side covering portion 61.

The semiconductor device A5 includes the resin composition 6, as withthe semiconductor device A1. The resin composition 6 covers the bondedregion (the die-pad-side bonded region or the lead-side bonded region)where conductive members (e.g., the conductive bonding material 4 or thefirst wires 31) and the lead frame 2 are bonded. Thus, in thesemiconductor device A5 again, malfunctions due to detachment of thesealing resin 5 are prevented, as with the semiconductor device A1.

In the semiconductor device A5, the resin composition 6 includes theelement-side covering portion 65. The element-side covering portion 65covers the bonded region of the second wire 32 and the secondfront-surface electrode 112, and the bonded region of the third wire 33and the third front-surface electrode 113. With such an arrangement, theresin composition 6 serves as an adhesive to improve the bondingstrength between the sealing resin 5 and the bonded region of the secondwire 32 and the second lead 22, as well as the bonding strength betweenthe sealing resin 5 and the bonded region of the third wire 33 and thethird lead 23. Thus, the semiconductor device A5 prevents detachment ofthe sealing resin 5 from these bonded regions, thereby preventingmalfunctions due to detachment of the sealing resin 5. With theprovision of the element-side covering portion 65, part of the elementfront surface 1 a (mainly the second front-surface electrode 112 and thethird front-surface electrode 113) is covered with the resin composition6. However, covering part of the element front surface 1 a with theresin composition 6 does not considerably degrade the heat dissipation,because during the operation of the semiconductor device A5 the secondfront-surface electrode 112 and the third front-surface electrode 113are less likely to generate heat as compared with the firstfront-surface electrode 111.

The fifth embodiment shows the example in which the element-sidecovering portion 65 covers part of the first front-surface electrode111, but the present disclosure is not limited to this. For example, theelement-side covering portion 65 may not cover the first front-surfaceelectrode 111. That is, the entirety of the first front-surfaceelectrode 111 may be exposed from the resin composition 6.

The fifth embodiment shows the example in which the resin composition 6includes the die-pad-side covering portion 61, the lead-side coveringportions 62, 63, 64 and the element-side covering portion 65, but theresin composition 6 may not include all of these. That is, it is onlynecessary that the resin composition 6 includes at least one of thesecovering portions.

Note that one or both of the lead-side covering portion 63 of the fourthembodiment and the element-side covering portion 65 of the fifthembodiment may be added to the semiconductor device A3.

The first through the fifth embodiments show the examples in which thesemiconductor element 1 has a vertical structure with the front-surfaceelectrode 11 and the back-surface electrode 12, but the presentdisclosure is not limited to this. For example, the semiconductorelement 1 may have a horizontal structure that does not include theback-surface electrode 12 (but includes the front-surface electrode 11).In this case, the conductive bonding material 4 may be Ag paste ratherthan solder.

The first through the fifth embodiments show the example in which thedie pad 24 of the lead frame 2 is exposed from the sealing resin 5 atthe pad back surface 24 b, but the present disclosure is not limited tosuch an arrangement, and the pad back surface 24 b may be covered withthe sealing resin 5.

The first through the fifth embodiments show the example in which thesemiconductor devices A1-A5 are of the surface mount type. However, thepresent disclosure is not limited to the surface mount type and is alsoapplicable to the lead insertion type. Also, in the semiconductor deviceA1-A5, the lead frame 2 projects from the sealing resin 5 as viewed inplan, but the present disclosure is not limited to this. For example,the present disclosure may be applied to e.g. a non-lead package type inwhich the lead frame 2 does not project from the sealing resin 5 asviewed in plan. In this way, the present disclosure is not limited tothe semiconductor device of a particular package type, but may beapplicable to various package types.

The semiconductor device and the manufacturing method according to thepresent disclosure are not limited to the foregoing embodiments. Thespecific configuration of each part of the semiconductor device and thespecific process in each step of the manufacturing method according tothe present disclosure may be varied in design in many ways.

The invention claimed is:
 1. A semiconductor device comprising: asemiconductor element having an element front surface and an elementback surface facing away from each other in a first direction, thesemiconductor element further having an element side surface connectedto the element front surface and the element back surface; a lead frameincluding a die pad and a lead spaced apart from the die pad, thesemiconductor element being mounted on the die pad; a conductive memberbonded to the lead frame, the conductive member electrically connectingthe semiconductor element and the lead frame; a resin composition; and asealing resin covering part of the lead frame, the semiconductor elementand the resin composition, wherein the conductive member incudes aconductive bonding material bonding the semiconductor element and thedie pad, the resin composition comprises a first portion covering atleast a part of the die pad, a second portion covering at least a partof the conductive member, a third portion covering at least a part ofthe element side surface, and a fourth portion covering at least a partof the element front surface, wherein the first portion, the secondportion, the third portion and the fourth portion are continuous witheach other.
 2. The semiconductor device according to claim 1, whereinthe die pad has a pad front surface facing a direction in which theelement front surface faces and a pad back surface facing a direction inwhich the element back surface faces, and the pad front surface and theelement back surface face each other.
 3. The semiconductor deviceaccording to claim 2, wherein the semiconductor element includes aback-surface electrode formed on the element back surface, and theconductive bonding material electrically connects the back-surfaceelectrode and the die pad.
 4. The semiconductor device according toclaim 3, wherein the conductive bonding material has an element contactsurface in contact with the back-surface electrode, a die-pad contactsurface in contact with the die pad, and a connecting surface connectedto the element contact surface and the die-pad contact surface, and thefirst portion of the resin composition is interposed between the atleast a part of the die pad and the sealing resin.
 5. The semiconductordevice according to claim 4, wherein the second portion of the resincomposition is interposed between the at least a part of the conductivemember and the sealing resin.
 6. The semiconductor device according toclaim 4, wherein the third portion of the resin composition isinterposed between the at least a part of the element side surface andthe sealing resin.
 7. The semiconductor device according to claim 6,wherein the fourth portion of the resin composition is interposedbetween the at least a part of the element front surface and the sealingresin.
 8. The semiconductor device according to claim 3, wherein theconductive bonding material comprises solder.
 9. The semiconductordevice according to claim 3, wherein the pad back surface is exposedfrom the sealing resin.
 10. The semiconductor device according to claim2, wherein the semiconductor element includes a front-surface electrodeformed on the element front surface, the conductive member includes awire bonded to the front-surface electrode and the lead to electricallyconnect the front-surface electrode and the lead.
 11. The semiconductordevice according to claim 10, wherein the wire includes a first bondpart bonded to the front-surface electrode and a second bond part bondedto the lead.
 12. The semiconductor device according to claim 11, whereinthe wire further includes a line part connecting the first bond part andthe second bond part, and the line part includes a sealing-resin contactregion that is in contact with the sealing resin along an entirecircumference thereof.
 13. The semiconductor device according to claim1, wherein the semiconductor element is a power semiconductor chip.